uniform vec3 BrickColor, MortarColor;
uniform vec2 BrickSize;
uniform vec2 BrickPct;

varying vec2 MCposition;
varying float LightIntensity;

void main(void) {
	vec3 color;
	vec2 position, useBrick;
	
	position = MCposition / BrickSize;

	if (fract(position.y * 0.5) > 0.5)
		position.x += 0.5;

	position = fract(position);
	
	useBrick = step(position, BrickPct);
	
	color = mix(MortarColor, BrickColor, useBrick.x * useBrick.y);
	color *= LightIntensity;
	gl_FragColor = vec4 (color, 1.0);
}	
 
